The invention relates to rotary shredders for shredding various materials, comprising a rotor and a counter knife.
Rotary shredders are used for shredding a variety of materials such as paper, cardboard, plastic film, cloth, webbing, textile fibers of natural or synthetic material, waste, and others. European Patent EP 419 919 B1 describes a shredder for such materials that includes a rotor having a plurality of circumferential ribs spaced apart along its length and a counter knife having teeth axially aligned with the valleys or grooves defined between the ribs of the rotor. A plurality of cutters are mounted in pockets formed in the outer surface of the rotor. Each cutter has two faces that are at a right angle to each other and form a V-shape that meshes with a correspondingly V-shaped recess between two adjacent teeth of the counter knife. Material fed into the space between the rotor and counter knife is cut into pieces by the cutters and the pieces pass through a screen that surrounds a portion of the circumference of the rotor; pieces too large to pass through the screen are carried by the rotor back to the counter knife to be cut again.
Further improvements in shredders of the above-noted type would be desirable.